Welcome to this GCSEbox

Please Feel Free to re-distribute this resource

Chemistry: The Atmosphere

This will cover:

Evolution of the Atmosphere

Todays Atmosphere

Todays Oceans

Evolution of the Atmosphere:

Things to note:

• The atmosphere is made up of primarily 78% Nitrogen, 21% oxygen and 0.04% Carbon Dioxide.

• Remaining 1% is made up of noble gases.
• There is also water vapour.

How the atmosphere was formed:

It was formed in three stages

1. Volcanoes Gave out Stream and Carbon Dioxide. The steam cooled and formed the oceans while the carbon dioxide filled the atmosphere.

2. Green plants evolved and produced oxygen. The plants used up carbon dioxide through photosynthesis also giving off oxygen into the air. Nitrogen was also released by plants and other living things.

3. Ozone layer allows evolution of complex animals as they could make use of the oxygen. Ozone layer also keeps out the sun's harmful rays.

The above process took roughly 4.5 billion years.

Todays Atmosphere:

Things to note:

• The atmosphere has been roughly the same for about 200 million years.

• It is made up of 78% nitrogen, 21% Oxygen, 1% Argon, 0.04% Carbon Dioxide
  

Todays Oceans:

Things to note:

• The oceans hold a lot of carbon

• They were formed by the condensation of steam in the early atmosphere
• Carbon Dioxide was absorbed from the atmosphere
• They currently contain large amounts of carbon in three major forms:

1. Carbon dioxide which has been dissolved in water

2. Insoluble carbonates like calcium carbonate
3. Soluble compounds like hydrogen-carbonates of Mg.

• Oceans getting saltier (slowly)

• Certain salts are removed through chemical and biological processes and dropped as sediment.
• Eventually these turn back into rock and the salts after millions of years return to the ocean.

This page is copyright to GCSEbox.com but may be freely re-distributed and presented. Information on this page has been provided to the greatest of accuracy but the reader must use this information at their own discretion.

Visit www.gamesfridge.com for over 500 free online games

In association with GCSEbox.com